UBSan: value is outside the range of representable values of type 'long'

[tsmith]

Summary of the bug:
UBSan: ffmpeg.c:4308:17: runtime error: value 9.22337e+18 is outside the range of representable values of type 'long'

How to reproduce:
Built with Undefined behavior sanitizer (-fsanitize=undefined)

./ffmpeg -f ivf -i test_case.ivf -f null -
ffmpeg version N-85548-g3390a2b Copyright (c) 2000-2017 the FFmpeg developers
  built with clang version 4.0.0-svn295380-1~exp1 (branches/release_40)
  configuration: --cc=clang --cxx=clang++ --disable-libxcb --disable-xlib --disable-logging --disable-ffprobe --disable-ffplay --disable-sdl2 --disable-ffserver --disable-doc --disable-pthreads --disable-network --disable-d3d11va --disable-dxva2 --disable-vaapi --disable-vda --disable-vdpau --disable-stripping --disable-runtime-cpudetect --disable-postproc --disable-securetransport --disable-iconv --disable-swscale --disable-avdevice --disable-videotoolbox --disable-everything --enable-encoder=wrapped_avframe --disable-lzma --enable-protocol='file,pipe' --enable-muxer=null --enable-demuxer=ivf --enable-parser=vp9 --enable-decoder=vp9 --disable-pic


ffmpeg.c:4308:17: runtime error: value 9.22337e+18 is outside the range of representable values of type 'long'
    #0 0x580737 in process_input ffmpeg.c:4308:17
    #1 0x580737 in transcode_step ffmpeg.c:4501
    #2 0x5709c5 in transcode ffmpeg.c:4550:15
    #3 0x5709c5 in main ffmpeg.c:4729
    #4 0x7fde51ac482f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #5 0x41a928 in _start (ffmpeg+0x41a928)

[Elon Musk]

No more reproducible.